As the doctrines of the gospel gradually undermined the popular belief in other spiritual beings inferior to the Deity, and were at the same time supposed to teach the existence and extensively diffused energy of an almost infinite and omnipotent agent of evil, it was exceedingly natural, nay, it necessarily followed, that the credulity and superstition which had led to the supposition of an alliance between philosophers and spiritual beings should settle down into a full conviction that the Devil was the being with whom they were thus confederated. The consequence was that they were charged with witchcraft, and many fell victims to the general prejudice and abhorrence occasioned by the imputation. The influence of this state of things was soon seen: it was one of the most effectual causes of the rapid diffusion of knowledge in modern times. Philosophers and men of science became as anxious to explain and publish their discoveries as they had been in former ages to conceal and cover them with mystery. The following instances will be sufficient to illustrate the correctness of these views. In the thirteenth century, Roger Bacon was charged with witchcraft on account of his discoveries in optics, chemistry, and astronomy; and, although he did what[i.342] he could to circulate and explain his own acquirements, he could not escape a papal denunciation, and two long and painful imprisonments. In 1305, Arnold de Villa Nova, a learned physician and philosopher, was burned at Padua, by order of inquisitors, on the charge of witchcraft. He was eighty years of age. Ten years afterwards, Peter Apon, also of Padua, who had made extraordinary progress in knowledge, was accused of the same crime, and condemned to death, but expired previous to the time appointed for his execution. I will now present a brief sketch of the most noticeable facts relating to the subject in Europe and Great Britain previous to the close of the seventeenth century. Some writers have computed that thirty thousand persons were executed for this supposed crime, within one hundred and fifty years. It will of course be in my power to mention only a few instances.